Rome, Feb 20 — Computer modelling has predicted parts of the Pacific experiencing the highest rates of rise in sea levels, while it may actually fall in some polar regions, owing to the interaction of sea, land and ice.
Researchers from the Universities of Urbino (Italy) and Bristol (Britain) have looked ahead to the year 2100 to show how ice loss will continue to add to rising sea levels.
Scientists have known that sea level rise will not be uniform, but the team of ‘ice2sea’ project researchers show in great detail the global pattern of sea-level rise that would result from two scenarios of ice-loss from glaciers and ice sheets, the journal Geophysical Research Letters reports.
Scientists from Urbino and Bristol found that ice melt from glaciers and the Greenland and Antarctic ice sheets is likely to be of critical importance to regional sea level change in the Equatorial Pacific Ocean where the sea level rise would be greater than the average increase across the globe.
This will affect in particular western Australia, Oceania and the small atolls and islands in this region, including Hawaii, according to an Urbino and Bristol statement.
The study focussed on three effects could cause global mean sea-level rise to be unequally distributed around the world.
Firstly, land is subsiding and emerging due to a massive loss of ice at the end of the last ice age 10,000 years ago when billions of tonnes of ice covering parts of North America and Europe melted.
This caused a major redistribution of mass on earth, but the crust responds to such changes so slowly that it is still deforming.
Secondly, the warming of the oceans leads to a change in the distribution of water across the globe.
Thirdly, the sheer mass of water held in ice at the frozen continents such as Antarctica and Greenland exerts a gravitational pull on the surrounding liquid water, pulling in enormous amounts of water and raising the sea-level close to those continents.
As the ice melts, its pull decreases and the water previously attracted rushes away to be redistributed around the globe.
Co-author Giorgio Spada, professor from Urbion, says: “We are successful in defining the patterns, known as sea level fingerprints, which affect sea levels.
“This is paramount for assessing the risk due to inundation in low-lying, densely populated areas. The most vulnerable areas are those where the effects combine to give the sea-level rise that is significantly higher than the global average.”
Co-author Jonathan Bamber of Bristol says: “This is the first study to examine the regional pattern of sea level changes using sophisticated model predictions of the wastage of glaciers and ice sheets over the next century.”